Abstract: In this review Frostytech will be testing out one of the latest hopefuls, the SilenX EFZ-100HA1 heatsink. This low profile cooler is a complex little bundle of heatpipes and fins, and stands only 67mm tall.

There is
great demand for low profile heatsinks to fit book-sized computer systems and
chassis conforming to 1.5U or 2U heights. The problem is there's not a lot to
choose from, particularly when searching out active (active = has fan) low profile heatsinks. In this review Frostytech
will be testing out one of the latest hopefuls, the SilenX EFZ-100HA1 heatsink. This
low profile cooler is a complex little bundle of heatpipes and fins, and
stands only 67mm tall. It features an exposed heatpipe base which is novel
as low profile heatsinks go, rubber vibration absorbing fan posts (overkill for the small fan), textured aluminum fins
and three 6mm diameter copper heatpipes.

In short, SilenX have tossed every popular heatsink technology into the
EFZ-100HA1 heatsink and capped it with a languid 100mm x 15mm vaneaxial fan.
Exhaust air is quietly directed down through the 17mm wide aluminum fins, so
that's a plus. The single 100mm non-PWM fan rotates at 1000-2000RPM depending on
the computer or manual fan speed controller setting. The entire heatsink weighs
just 364 grams and installs onto Intel socket 775/1156/1366 and AMD socket
754/939/940/AM2/AM3 processors. Expect retail prices in the $20-$28USD range.

The odd thing when looking at this heatsink is how much
of it, isn't heatsink. You see, heatpipes have a minimum bend radius, so
unfortunately much of the space this heatsink could occupy for its aluminum
cooling fins is lost to the heatpipes inflexibility when it comes to right
angles. What's left is a thin margin of aluminum to dissipate heat loads that
span upwards of 140W TDP. The SilenX does manage it however. The real
question this review will answer is how well it manages to cool compared to
other sub 67mm tall heatsinks.

Topping the SilenX EFZ-100HA1 low profile heatsink is
a SilenX "Effizio series quiet fan" that rotates by default at 2000RPM. The fan
is quite small, just 100 x 100 x 15mm in size and packs in eleven
white impeller blades.

Below the fan is a rather unique treatment for the
leading edges of the textured aluminum fins. A shallow concave curve in
the center forms the plenum while the extremities look like little Tsunami's expanding towards the
outer edge.

The 17mm wide aluminum fins are press fit over
the 6mm diameter copper heatpipes, but not exactly evenly. The three heatpipes are doubled over so in effect we're
dealing with six heatpipe ends. One half of the SilenX EFZ-100HA1 heatsink has two
heatpipes, the other side four. The apparently asymmetrical heat distribution is a tricky thing to comment
on. Without additional information we can't say what impact this has on the overall performance
of SilenX's EFZ-100HA1 heatsink...

Heatsink Mounting Hardware

The low
profile SilenX EFZ-100HA1 heatsink ships with the same fairly massive mounting
brackets as SilenX uses for full size CPU coolers when a much simpler and more compact bracket
would easily suffice for this 364gram heatsink. The EFZ-100HA1 supports Intel LGA775/1156/1366 and AMD 754/939/940/AM2/AM3 processors via the same permanently affixed metal bracket pictured below.

A
collection of screws and spring-tensioned nuts accommodate the variety of hole
patterns for the range of processors the EFZ-100HA1 heatsink is compatible
with. Eight rubber vibration absorbing fan posts are supplied (only one
100mm fan may be installed) along with a manual fan speed controller and small
amount of thermal compound. Access to the rear of the motherboard is needed to
insert the motherboard support plate. This may pose difficulties as low profile
computer systems are not usually built with cut outs behind the CPU socket.

FrostyTech's Test Methodologies are outlined in detail here if you care to know what equipment is
used, and the parameters under which the tests are conducted. Now let's move
forward and take a closer look at this heatsink, its acoustic characteristics,
and of course its performance in the thermal
tests!